Camping in the outdoors can create unwanted encounters with dangerous wildlife such as bears, moose, elk, or other intruders. These intruders often enter campsites in the evening when campers are asleep or during the day when campers may be distracted by other activities. By the time the campers realize the intruder is in the camp, it may be too late to prevent serious injury or death.
In another scenario, sometimes a child play area is by necessity near a dangerous area. In the absence of a physical boundary, there is need for a boundary sensing method which can alarm when a perimeter is breached.
This system must also be capable of discriminating between objects like, but not limited to small animals, tree branches, balls, etc. and larger, more relevant objects like children, adults, or other larger animals. In order to be useful, the system needs to be easily configurable for a variety of operational environments. The need is to allow movement within a portable boundary, but alert when the perimeter is sufficiently obstructed.
There have been some developments in the arena of motion sensing, but they practically fail to meet this need.
Some systems use a physical boundary which is set up by the user. A physical boundary, like a tripwire, is incapable of distinguishing between the various entities which may trip the wire. Also, once the wire is tripped, the system must be setup again and is inconvenient for perimeter monitoring. In an outdoors environment, large animals may intentionally or unintentionally simply step over the triggering device.
There are other systems which make audible alarms or turn on lights when motion is detected, however they generally fail to discriminate between smaller objects and more significant ones. In an outdoors environment, such a system is not useful if, for example, it cannot distinguish between branches blowing in the wind, and a large animal.
Some systems use lasers to establish a defined perimeter. Although the laser beams allow movement within the perimeter and adequately create a boundary, the system is triggered when there is a break in the beam or link between two sensors. This beam may be broken by either small or large objects and a laser based system cannot distinguish between the two. Additionally, would be intruders may simply miss the beam and cross the perimeter without triggering the system. Lasers are also impractical for a variety of settings because they require large amount of power not generally available to a portable user.
Arrays of infrared sensors are sometimes used to monitor a given boundary. Although this type of method, monitors movement on a given boundary, it still cannot discriminate between the movement of irrelevant objects and larger ones. Currently designed systems are expensive, require permanent installation and amount of power not generally available to a portable user. Also, in this scenario, the individual sensors do not cooperate and include no deterrent.
There is a need for a boundary system that is capable of differentiating between acceptable movement by irrelevant objects and larger objects of interest in a wide variety of environments. The system should be able to immediately alert users, or deter intruders, be portable, lightweight and easy to set up.